Cross-country skiing is a highly-popular winter sport throughout the United States and much of the world. While it is always desirable to ski in well-packed, fine snow powder, skiers do not always have this choice. Often, following a rain or a warmup followed by a freezedown, cross-country skiing paths will become riddled with icy spots, which makes skiing more difficult and hazardous.
The predominant leg motion of cross country skiing on a flat or uphill skiing surface involves taking a sliding step forward with one ski, while pushing back--ideally with minimal slippage--on the other ski. The predominant arm motion, in synchronization with this, is to plant one pole in the ground and push backward to gain traction for the sliding leg step forward, and to freely swing the other pole forward for replanting in the ground to aid the subsequent step forward. Generally, the left leg and the right arm push backward at the same time as the right leg and left arm move forward, and vice-versa.
While the backward pole push is the primary means for gaining traction in order to slide the skis forward, sometimes this is not sufficient. In icy conditions, the pole may not insert well into the ice, and the ski pushing backward cannot acquire enough traction and will slip backward rather than planting firmly and aiding the forward sliding of the opposite ski. It would, therefore, be desirable to have a simple device and method for improving ice traction, via the skis themselves.
The prior art reveals some attempts to address this problem, all of which fall short of an optimum solution. In general, the primary approach is to introduce an "asymmetry" into or onto the ski, so that the ski slides easily and offers minimal resistance when it is moved forward, while it plants firmly and offers solid traction when it is pushed backward.
U.S. Pat. Nos. 4,027,895; 4,118,050; 4,272,577; 4,323,265; 4,595,215; 4,635,954; and 4,919,447 all integrate some form of asymmetry directly into the fabrication of the skis themselves, involving, e.g., dual surfaces (U.S. Pat. No. 4,027,895), three-dimensional surfaces (U.S. Pat. No. 4,118,050), asymmetrically embedded particles (U.S. Pat. No. 4,272,577), fish-like scales (U.S. Pat. No. 4,323,265), grooves (U.S. Pat. No. 4,595,215), material coatings (U.S. Pat. No. 4,638,954), and fibers (U.S. Pat. No. 4,595,215). However, all of these solutions integrate fully with the fabrication and manufacture of the skis themselves. They are not at all useful to add traction to preexisting skis, not can they be employed for new skis without changing the fundamental design of the skis.
Add-on devices such as disclosed in U.S. Pat. Nos. 4,227,708; 5,516,141 and 5,642,897 are used as ski brakes, i.e., to stop the skis from moving forward. But what is needed here is a device to add traction, i.e., to stop the ski from moving backward. U.S. Pat. No. 4,363,497 is a traction device, but it is cumbersome to use, and in particular, requires engagement by the ski pole itself.
U.S. Pat. Nos. 4,148,500; 4,596,400; 4,674,764; 4,898,401; 5,221,104; and 5,577,754 appear to provide some added backward traction independent of the ski poles. However, these devices are all fairly complex involving numerous parts and springs, their attachment to a ski is complicated, and several appear to interfere with the ski in an undesirable manner.
Even for downhill skiing, there are times when a skier finds it necessary to walk forward on a ski, or perhaps up a section of hill, and it would be helpful if there existed an aid to gain traction for such an uphill walk.
Thus, would be desirable to have a traction device that is simpler, that is more easily added to the ski, and that operates only by virtue of the motion of the ski, totally independent of the ski pole.